1. Field of the Invention
The present invention relates to an electrocardiograph system and a communication device for it.
2. Description of the Related Art
It is generally known that different cardiograms can be obtained depending on the postures of the subject (the person being diagnosed). Even if the subject is healthy, changes may occur on cardiograms simply due to a change in the postures of the subject. In order to eliminate the effects of posture changes so that proper diagnosis can be made, the device user such as a medical operator must prepare in advance by recording typical cardiograms of the subject at various postures on recording paper as the reference cardiograms. In analyzing the cardiogram obtained for a predetermined time period, the user must compare the cardiograms of the subject with the reference cardiograms. As a result, the user will be able to judge if a change on a cardiogram is due to a posture or illness of the subject.
Cardiograph systems are proposed in recent years wherein reference cardiograms are recorded in the memory devices built into the electrocardiographs instead of recording on paper so that the cardiograms collected in actual diagnoses can be compared with the reference cardiograms by computers.
For example, the Japanese Patent Application No. 9-56687 filed on Aug. 22, 1995 disclosed a cardiogram measuring system. The cardiogram measuring system is equipped with a portable electrocardiograph capable of storing obtained cardiograms and an analyzing device that receives the cardiograms from the electrocardiograph and analyzes them.
The portable electrocardiograph has a capability of measuring and storing reference cardiograms in advance of measuring cardiograms to be analyzed. The portable electrocardiograph itself is equipped with multiple switches. Specifically, it is equipped with switches corresponding to the side lying, standing, walking and running conditions. For example, in order to produce a reference cardiogram for the side lying condition, the subject lies on the side of his/her body while turning on the switch for the lying condition. A cardiogram for the side lying condition is then produced and stored in the memory, after which follows a process of measuring for the predetermined time period a cardiogram to be analyzed.
However, the above-mentioned cardiogram measuring system has the following problems. Since the portable electrocardiograph for measuring and storing cardiograms is equipped with components such as switches for selecting the conditions of the subject, it is difficult to reduce the size of the portable electrocardiograph that is to be attached to the subject. Moreover, it is difficult to make it waterproof because of the components such as switches.
Moreover, while the patent publication disclosed the idea of storing the reference cardiograms corresponding to simpler conditions of the subject, it failed to disclose the idea of storing reference cardiograms corresponding to more specifically classified postures. Consequently, it is impossible to store reference cardiograms corresponding to more specifically classified postures including a standing, a face-up lying, a right side lying, and a left side lying. For the purpose herein, the standing position denotes the position wherein the subject is standing, the face-up lying position denotes the position wherein the subject is lying on his/her back, the right side lying position denotes the position wherein the subject is lying on his/her right side of the body, and the left side lying position denotes the position wherein the subject is lying on his/her left side of the body.
Further, it is difficult for the cardiogram measuring system to display for confirmation the waveforms of reference cardiograms as static images corresponding to the standing, face-up lying, right side lying or left side lying positions respectively, while displaying as time-varying images the waveforms of cardiograms produced in real time. Therefore, even when proper reference cardiogram production is hindered due to malfunction of electrodes, the cardiograph production may proceed without correcting the problem.
It is an object of the present invention to provide an electrocardiograph system and its communication device that are capable of measuring and storing the cardiograms for reference corresponding to various postures of the subject based on remote instructions using wireless signals from the outside without having to have a control unit containing switches in the portable cardiograph for selecting the subject""s posture from various posture options.
It is another object of the present invention to provide an electrocardiograph system that displays the reference cardiograms as static images, while displaying waveforms of obtained cardiograms in real time as time-varying images or as static images in case of need.
According to an aspect of the present invention, an electrocardiograph system has an electrocardiograph that produces cardiograms and transmits the produced cardiograms, and a communication device that wirelessly communicates with the electrocardiograph. The communication device accepts a subject""s posture selected from multiple posture options and transmits a predetermined instruction signal to the electrocardiograph when the posture is accepted. The electrocardiograph stores the cardiogram produced when said instruction signal is received from said communication device, as a reference cardiogram corresponding to the selected posture.
According to another aspect of the present invention, an electrocardiograph system has an input circuit producing cardiograms based on electrical potential changes detected by biological electrodes, an operating unit accepting a subject""s posture selected from multiple posture options, a memory storing a cardiogram produced by the input circuit when the operating unit accepts a posture selection as the reference cardiogram corresponding to the selected posture discriminating it from other cardiograms, and a display displaying as a static image the waveform of the reference cardiogram, while sequentially displaying as time-varying images waveforms of cardiograms produced time-sequentially by the input circuit.
According to still another aspect of the present invention, a communication device wirelessly communicating with an electrocardiograph has an operating unit accepting a subject""s posture selected from multiple posture options, a transmitting unit transmitting a predetermined instruction signal to the electrocardiograph when the posture is accepted, and a receiving unit receiving a cardiogram produced by the electrocardiograph when the electrocardiograph receives the instruction signal as the reference cardiogram corresponding to the selected posture discriminating it from other cardiograms.